/*
 * A C++ Config Class from Internet
 * It works well.
 */
#ifndef CONFIG_H_
#define CONFIG_H_


#include <string>  
#include <map>  
#include <iostream>  
#include <fstream>  
#include <sstream>  

      
/* 
 * \brief Generic configuration Class 
 * 
 */  
class Config {  
  // Data  
 protected:  
  std::string m_Delimiter;  //!< separator between key and value  
  std::string m_Comment;    //!< separator between value and comments  
  std::map<std::string,std::string> m_Contents;  //!< extracted keys and values  
  
  typedef std::map<std::string,std::string>::iterator mapi;  
  typedef std::map<std::string,std::string>::const_iterator mapci;  
  // Methods  
 public:  
  
  Config( std::string filename,std::string delimiter = "=",std::string comment = "#" );  
  Config();  
  template<class T> T Read( const std::string& in_key ) const;  //!<Search for key and read value or optional default value, call as read<T>  
  template<class T> T Read( const std::string& in_key, const T& in_value ) const;  
  template<class T> bool ReadInto( T& out_var, const std::string& in_key ) const;  
  template<class T>  
  bool ReadInto( T& out_var, const std::string& in_key, const T& in_value ) const;  
  bool FileExist(std::string filename);  
  void ReadFile(std::string filename,std::string delimiter = "=",std::string comment = "#" );  
  
  // Check whether key exists in configuration  
  bool KeyExists( const std::string& in_key ) const;  
  
  // Modify keys and values  
  template<class T> void Add( const std::string& in_key, const T& in_value );  
  void Remove( const std::string& in_key );  
  
  // Check or change configuration syntax  
  std::string GetDelimiter() const { return m_Delimiter; }  
  std::string GetComment() const { return m_Comment; }  
  std::string SetDelimiter( const std::string& in_s )  
  { std::string old = m_Delimiter;  m_Delimiter = in_s;  return old; }    
  std::string SetComment( const std::string& in_s )  
  { std::string old = m_Comment;  m_Comment =  in_s;  return old; }  
  
  // Write or read configuration  
  friend std::ostream& operator<<( std::ostream& os, const Config& cf );  
  friend std::istream& operator>>( std::istream& is, Config& cf );  
  
 protected:  
  template<class T> static std::string T_as_string( const T& t );  
  template<class T> static T string_as_T( const std::string& s );  
  static void Trim( std::string& inout_s );  
  
  
  // Exception types  
 public:  
  struct File_not_found {  
    std::string filename;  
    File_not_found( const std::string& filename_ = std::string() )  
        : filename(filename_) {} };  
  struct Key_not_found {  // thrown only by T read(key) variant of read()  
    std::string key;  
    Key_not_found( const std::string& key_ = std::string() )  
        : key(key_) {} };  
};  
      
      
/* static */  
template<class T>  
std::string Config::T_as_string( const T& t )  
{  
  // Convert from a T to a string  
  // Type T must support << operator  
  std::ostringstream ost;  
  ost << t;  
  return ost.str();  
}  

      
/* static */  
template<class T>  
T Config::string_as_T( const std::string& s )  
{  
  // Convert from a string to a T  
  // Type T must support >> operator  
  T t;  
  std::istringstream ist(s);  
  ist >> t;  
  return t;  
}  

      
/* static */  
template<>  
inline std::string Config::string_as_T<std::string>( const std::string& s )  
{  
  // Convert from a string to a string  
  // In other words, do nothing  
  return s;  
}  

      
/* static */  
template<>  
inline bool Config::string_as_T<bool>( const std::string& s )  
{  
  // Convert from a string to a bool  
  // Interpret "false", "F", "no", "n", "0" as false  
  // Interpret "true", "T", "yes", "y", "1", "-1", or anything else as true  
  bool b = true;  
  std::string sup = s;  
  for( std::string::iterator p = sup.begin(); p != sup.end(); ++p )  
    *p = toupper(*p);  // make string all caps  
  if( sup==std::string("FALSE") || sup==std::string("F") ||  
      sup==std::string("NO") || sup==std::string("N") ||  
      sup==std::string("0") || sup==std::string("NONE") )  
    b = false;  
  return b;  
}  


template<class T>  
T Config::Read( const std::string& key ) const  
{
  // Read the value corresponding to key  
  mapci p = m_Contents.find(key);  
  if( p == m_Contents.end() ) throw Key_not_found(key);  
  return string_as_T<T>( p->second );  
}  


template<class T>  
T Config::Read( const std::string& key, const T& value ) const  
{  
  // Return the value corresponding to key or given default value  
  // if key is not found  
  mapci p = m_Contents.find(key);  
  if( p == m_Contents.end() ) return value;  
  return string_as_T<T>( p->second );  
}  


template<class T>  
bool Config::ReadInto( T& var, const std::string& key ) const  
{  
  // Get the value corresponding to key and store in var  
  // Return true if key is found  
  // Otherwise leave var untouched  
  mapci p = m_Contents.find(key);  
  bool found = ( p != m_Contents.end() );  
  if( found ) var = string_as_T<T>( p->second );  
  return found;  
}  


template<class T>  
bool Config::ReadInto( T& var, const std::string& key, const T& value ) const  
{  
  // Get the value corresponding to key and store in var  
  // Return true if key is found  
  // Otherwise set var to given default  
  mapci p = m_Contents.find(key);  
  bool found = ( p != m_Contents.end() );  
  if( found )  
    var = string_as_T<T>( p->second );  
  else  
    var = value;  
  return found;  
}  

      
template<class T>  
void Config::Add( const std::string& in_key, const T& value )  
{  
  // Add a key with given value  
  std::string v = T_as_string( value );  
  std::string key=in_key;  
  Trim(key);  
  Trim(v);  
  m_Contents[key] = v;  
  return;  
}

#endif
